def sayhello():
    print('hello')


# print('执行函数前')
# # 必须在后面才能用
# sayhello()
# print('执行函数后')

def sum1and2(a, b):  # a和b是形参
    print(f'求和结果{a + b}')
    return a * b


result = sum1and2(2, 8)  # 2和8是实参
print(f'{result}')
